1. Field of The Invention
The invention relates to an electrical connector for electrically connecting a daughter board and a mother board, and particularly to an electrical connector having a board retaining means for reliably and releasably latching an inserted daughter board.
2. The Prior Art
As known, for raising or increasing some requested functions, most of computer systems with mother boards provide a plurality of specific electrical connectors to receive different daughter boards, as generally called "the extensive cards", having some electrical apparatus or chips thereon. Such electrical connector mainly forms an elongated slot having a plurality of contacts for electrically receiving the corresponding daughter board therein, and is further deposited with a pair of board retaining means at opposed ends thereof for latching the daughter board. The designs regarding such electrical connectors with a board retaining means can be referred to U.S. Pat. Nos. 3,993,390, 4,057,879, 4,832,617, 4,986,765, 5,286,217, 5,372,518 and 5,383,792, and Taiwan Patent Application Nos. 78,102,902, 79,211,470, 80,200,008, 80,110,023 and 82,217,323.
However, the conventional board retaining means merely accommodates a light daughter board which is just mounted with some micro-chips thereon. When another type daughter board mounted with some heavy electrical apparatus like a CPU (Central Process Unit) and a micro-fan for dissipation heat, is installed in the conventional electrical connector, the inserted daughter board may lean toward one side of the connector to result in a poorly electrical contact between the connector and the daughter board, due to a center of gravity of the board daughter board being unstable. If such connector receiving the heavy daughter board is further located in a vibrating environment, said poor contact condition may be worsened.
Accordingly, for resolving the above disadvantages, an object of the invention is to provide an improved electrical connector which mainly includes a first housing, a second housing and a board retaining means for providing a fine retentive effect with respect to an inserted daughter board, especially to a heavy daughter board, and for maintaining a reliably electrical contact. The first housing forms an elongated slot therein for receiving a daughter board. The second housing is designed with a pair of supporting portions each having a cavity portion for installation with a corresponding board retaining means, and having two opposed guiding rails for clamping and guiding the insertion of the daughter board with regard to the first housing. The board retaining means is defined with an acting portion, a first resilient portion, a latching portion, a second resilient portion and a retentive portion.